Interpretive Summary: Pink bollworm is a major economic cotton pest that had recently been eradicated from zones in western Texas and southeastern New Mexico, but several hundred pink bollworm moths were captured after a two-year absence of this pest. Therefore, new information is needed to identify and eradicate the source of pest re-infestation. A trapping study was conducted to precisely identify and subsequently eradicate the source of pink bollworm moths that was contributing to re-infestation of the western Texas and southeastern New Mexico eradication zones. Trap data indicated that two non-Bt organic cotton fields in southern Midland County, Texas, comprised the likely source of pink bollworm moths in 2010-2011. Eradication efforts in 2012 resulted in no additional moths captured that fall, suggesting the local population had been eradicated. These results demonstrate the value of areawide insect trapping for detection and strategic deployment of pest management resources relative to pest re-infestations.

Technical Abstract:
Pink bollworm, Pectinophora gossypiella (Saunders), is one of the most economically important insect pests of cotton, Gossypium hirsutum L., in the world. Losses in the U.S. before widespread use of Bt cotton were estimated at $32 million per year. Eradication programs were initiated in the El Paso/Trans Pecos area of Texas in 2001 and South Central New Mexico in 2002. In 2009, 669 pink bollworm moths were captured in the El Paso/Trans Pecos eradication zone after two consecutive years of no captures. A study in 2010-2011 determined the source might be nearby areas of West Texas and southeastern New Mexico outside of eradication zones. A likely source of pink bollworm moths was identified in southern Midland County. In 2010, 1,438 moths were captured, with 85% trapped in two fields of non-Bt organic cotton. More than 99% were collected within an 8-km radius of that epicenter. Only 0-10 pink bollworms were captured in each of three other areas monitored in 2010.
In 2011, no pink bollworm moths were caught in any area surveyed, except in a small area in southern Midland County. Pink bollworm moths were captured in seven fields in the area, with a total of 119 moths from May-August 2011. Seventy-two percent of pink bollworm moths captured were from the two fields of non-Bt, organic cotton. Trapping in the fall, September through early November 2011, detected pink bollworm activity in the area. Seven hundred twenty-nine moths were captured from seven fields, 97% from the two non-Bt, organic fields. Because most fields in the region are planted to Bt cotton, it is likely that reproducing pink bollworms in the two fields, less than 40 hectares, were the only source of wild pink bollworm moths in the El Paso/Trans Pecos eradication zone (526,091 hectares of cotton) in 2009. Eradication efforts in 2012 resulted in no additional moths captured that fall, suggesting the localized population was eradicated.